AC vs Microwave Use

[tnchuck100]

Originally Posted by wags999

you are possibly putting your shore power cord at risk. If a short was to happen between the pedestal and your break box inside, your cord, which is sized for 30 amps, could pull up to 50 amps, before tripping the pedestal breaker. This could result in a complete failure of the power cord. Plugging into a 50 amp breaker does nothing to get you more or more reliable power to your rig. If you have an issue with the 30 amp tripping on the pedestal and not in your rig, then I would alert the campground so that breaker can be changed, they can weaken over time. Breakers are there to prevent issues in your rig, they are designed as the weak link in the system, to prevent problems.

The probability of having a service cable failure is extremely low. Allowing it has had reasonable care and does not have visible damage. If the service cable did happen to develop a short it WILL instantly trip that 50 amp breaker at the pedestal.

Using the 50/30 adapter is a good choice if the 30 amp receptacle is worn and not providing a solid connection. Getting the campground to change a bad 30 amp receptacle might not be done in a timely manner. Given this situation the 50 amp receptacle with the appropriate adapter will provide more reliable power. Not more amps just more reliability. Your 30 amp main breaker in the RV will still limit your draw.


Additionally, the breakers in the pedestal are there to protect the campground equipment not your RV.

[wags999]

Wrong the breakers in the pedestal only protects your RV, the breaker on the line going to the pedestal is what protects the campground lines.

[nylyon]

Using this chart: RV Converters and Amp Draw - RV Information (RV Maintenance) it says that the A/C uses 12-16 Amps, and the Microwave 13 Amps. So at minimum the A/C and Microwave use 25 Amps, and Maximum 29.

Assuming that the A/C and Microwave are on separate circuits in the RV, you would likely be tripping the main breaker. In that case, you need to lessen the draw. Water heater and fridge are good candidates to turn to gas only.

The fix is to upgrade to 50A service. Work arounds include reducing your electric draw, or even running a separate electric cord for the Microwave. In my last TT, I could use the A/C (assuming it didn't cycle) and the Microwave at the same time, but fridge and water heater had to be on gas only.

[AKGperson]

While researching how a CG 50 amp outlet is wired, I found this URL:

http://www.myrv.us/electric/

It shows two 120v hots connected to a 2-pole 50 amp breaker whereas the 30 amp breaker is single pole. (Keep in mind that both wires must be coming off the same buss in the main service panel otherwise you will have a 240 volt outlet that will fry everything in a TT or RV with a 50 amp system.)

I assume the 50 amp to 30 adapter passes through just one hot giving you just 30 amps. In that case, I wouldn't be worried about overheating wires by using an adapter on a 30 amp system.

By the way, I like the autoformer and will add a volt meter to my tool box because I know that undervoltage is a real motor killer.

Ken

[wags999]

Originally Posted by AKGperson

I would never recommend hooking a 30 amp system into a 50 amp circuit for fear of overheating the wiring. There is a good reason why 30 amp & 50 amp circuits have different plug configurations. It's because they have different gauges of wires and main circuit breakers. The higher the amperage, the larger the wire must be to properly carry the load and withstand the heat buildup.

Look at the difference in wire sizes the next time you go into Camping World and pick up a 50 amp & a 30 amp pigtail.

Personally, I wouldn't be able to fall asleep in a TT that I knew was wired improperly.

With that said, I do like the autoformer and will add a volt meter to my list of tools because undervoltage is a real motor killer.

Ken

Actually the 50 amp is a 240 volt plug. You have two 50 amp, 120 volt lines compared to one 30 amp 120 volt line with a 30 amp service. That is why if the pedestal with two 30 amp plugs are not wired properly you would have a major issue. On the 50 amp service, one leg 120 volts each is on one leg coming into the campground and the other leg is on the other leg coming into the campground. If, both of the 30 amp plugs were on the same leg coming into the campground, you would have an issue with the neutral. You run a 240 system with one neutral and one breaker on each leg of the 240 system. With the 30 amp, your running each separately, with it's own neutral. But when you connect through a dog bone, and plug in twice, you risk each leg being on the same side of the incoming power, and you still only have one neutral. Electricity is alternating meaning it cycles 60 times per second. It comes in through the power leg and out thru the neutral, with two lines on one neutral you will get issues with the common neutral. Not a chance I would be willing to take.

It also is why it's not an easy upgrade from 30 amp to 50 amp. A 30 amp rig has a total of 30 amp at 120 volts or 3600 watts of power available. A 50 amp system has two 50 amp 120 volt giving you 100 amps at 120 volts or 12,000 watts of power...HUGE difference. You get 3 1/3 times MORE power with a 50 amp system than you get with a 30 amp system. It's why typically it costs more to get a 50 amp site, they are more expensive to install, and, you use more electric. I would stick with what your rig came with, adjust your needs to fit what is available, and if need be, use a 12/3 heavy duty extension cord for extras like electric heaters etc.

If there is a problem with a plug at the campground I'm sure it would be take care of immediately or, you would be moved to a different sight. This has not been a major problem at the camp grounds i Have worked at. More of an issue is someone plugs into a GFIC and it blows, they think it is the breaker, when, it is their rig. I bet I have not changed out more than two breakers and rarely a plug in the course of a year. We check them all at the start of the season and rarely have issues after that.

Good Luck ... just get use to what you can and can't run at the same time. A 6 gal electric water heater can draw about 1400 watts or 12.5 amps, a refrigerator from 400 to 1200 watts or 3.5 to 10.4 amps. Typically with a 30 amp rig it will be on the lower end.

[AKGperson]

Not true, WAGS. Most TTs & RVs are not wired for 240 volts. Both 120v hots for a 50 amp panel are coming off the same buss bar in the CG main service panel thereby providing higher amperage but not higher voltage.

By the way, after posting what you quoted from me, I did some research and revised the post based on a URL showing how CG outlets are wired and how 2-pole 50 amp breakers are used in TTs & RVs. I assume they wire them that way to reduce the size of the wiring required to carry the amperage. In a standard house we would run one properly sized hot wire for 120v.

Ken

[wags999]

That is wrong. You have to have one on each leg with a single neutral. I have wired campgrounds trust me. No RV are not wired for 240 but if you have 50 amp system it is two 120 volt lines one on each leg coming into your rig. With a single neutral wire and a ground wire. They DO NOT come off the same leg at the main in the campground, in fact it is a 240 typically 60 to 100 amp breaker coming into your pedestal, it also will serve a pedestal down the row from you. So on the main campground breaker panel you will have one large (100 amp) breaker serving two 50 amp pedestals. It is 240 volt but your rig breaks them down to two separate 120 volt legs, on one neutral.

[wags999]

When you have two breakers connected together in a panel, it is 240 volts. In a panel every other breaker is on a different leg. As you go down breaker position one is on one leg, two is on the other leg. Breakers across from each other are on the same leg, next to each other (top/bottom) are on different legs. It gets confusing, but, having had an electrical license for years and having worked in Campgrounds, where typically I take care of most of the electrical issues, I can say with 100 confidence that a 50 amp service IS two 120 volt 50 amp lines hence.. 240 volts service. and a 30 amp service is 120 volt single line service. Inside your rig yes you use only 120 volts typically, dryers can be 240 volt. But you get 2 120 volt 50 amp lines for a total of 100 amps at 120 volts.

[AKGperson]

As I said, (and I think you just said) TTs & RVs are not wired for 240 volts so why would you have, or need, 240 volts at the pedestal? And trust me, you don't have to have 2 hots to make a 50 amp circuit. There are many 50 amp single pole breakers available. Size of wiring is the only reason I can think of.

Ken

[wags999]

Some RV ARE wired for 240 such as Dryers... You need two hots to make a 50 amp RV service. Yes you can have 50 amp 120 volt lines, but that is not what you have with an RV. An RV has either a single 30 amp line at 120 volts, or two 50 amp lines at 120 volts. This gives you 3600 watts on the 30 amp system or 12,000 watts on the 50 amp system. No RV uses a single 50 amp line, and no campgrounds are wired for a 50 amp 120 line, If you look at the breaker you will have a single 30 amp, or a dual 50 amp breaker. You typically will have a 20 amp 120 volt standard plug also. I have never seen a dual 30 amp line, and not sure why they would do that. But you do have 240 available at the pedestal. When you run a 240 system you only need one neutral wire, if you had two 50 amp breakers on the same phase (leg) you would need two neutrals, you can't run two circuits be it 15 amp or 200 amp on a single neutral, unless they are phased (one on each leg).

[wags999]

Your 50 amp trailer has 100 amps of power available at 120 volts.
A 30 amp trailer has 30 amps of power available at 120 volts.

Check the breaker in the pedestal next time, it will be a double for your 50 amp service.

It's also why you have 4 plugs on a 50 amp service and 3 on a 30 amp. The extra plug is for the extra hot ....two hots on 50 amp, one hot on 30 amp, one neutral on each and one ground on each. Hope this clarifies, know it's very confusing.

To confuse you more.. a typical pedestal will have two hot wires coming in, then you will have one dual breaker 50 amp supplying the 50 amp plug, one 30 amp breaker supplying the 30 amp plug and one 20 amp breaker supplying the standard outlet. All coming off the two hot legs coming in. Breakers immediately above or below the next are on different legs, breakers across from each other are on the same leg. This is how your panel in a stick and brick home is also.

[RVhiker]

Originally Posted by RVhiker

You can probably use the AC and microwave at the same time if you run both the refrigerator and water heater on electric.

Originally Posted by SmokerBill

Don't you mean "run both the refrigerator and water heater on propane"?

Thanks for catching that, SmokerBill. My brain must have been temporarily on vacation. As in my signature line, "There's lots of advice and information in forums... sometimes it is correct. "

[AKGperson]

Wags, I can now see why each pedestal has 240 (to save wire by eliminating one neutral) and, being a General Contractor, I know how a typical service panel staggers the legs (1,3,5,7 on one side vs 2,4,6,8 on the other side) in a stick & brick home.

Ken

[wags999]

Yep Ken, sometimes when I try to make it simple to understand, it just gets more complicated LOL Also a 100 amp single line with neutral and ground would be a Huge wire, much much harder to wind up than your current shore cord. I will say Electric and the difference between 30 amp rv's and 50 amp rvs are probably the most misunderstood part of an RV. When I tell people that you will have 1/3 the available power if you plug a 50 amp into a 30 amp outlet, they get that screen saver look in their eyes LOL

Spring is tomorrow. Camping around the corner ! Hope everyone has a great season, hope to see some of you along the road.